1. Field of the Invention
The present invention relates to chemical mixers, and more particularly, the present invention relates to a chemical mixer which maintains a minimal chemical fluid level, and replenishes the fluid level by adding water up to an adjustable maximum level, so that dry chemicals can be added to give a proper chemical concentration to the mix. The maximum level is adjustably set depending on manufacturers' chemical-water mix specifications as to the dry chemical or liquid concentrate to be mixed.
2. General Background and Prior Art
The use of chemicals in different types of processes usually requires a chemical which has been tightly controlled as to quality. In many systems, variations in the concentrate of different components of a given chemical in the process can bring undesirable and unforeseen results. This is especially true in the photographic processing industry, where the control of processing chemicals such as developers and fixers must be maintained in order to provide high quality finished photographs or negatives. The same holds true in the X-ray field as well.
Generally, chemicals are shipped from a manufacturer to individual users, and this is most often done in the dry or liquid concentrate chemical form for both safety, economy and convenience. The dry and liquid concentrate chemicals are lighter and thus more economical to ship. Dry chemicals also can be packed in cardboard or like unbreakable containers not as susceptible to spilling and breaking.
This creates a great need for a device and method for preparing the dry or liquid concentrate chemicals properly so that the manufacturers' specifications and hence overall quality is maintained by the individual who mixes the chemical prior to their actual use in a given process. This can be done in a variety of ways such as hand mixing or batch preparation which is discontinuous and time consuming.
Generally, the manufacturer will specify the amount of water to be added to his dry chemical packaged mix or liquid concentrate. Unfortunately, manufacturers do not maintain a standard chemical concentrate, even within like industries, such as the photographic processing industry. Thus, the usual manner for mixing chemicals is hand mixing wherein the amount of water is ascertained, added to a suitable container, thereafter the dry chemicals are emptied into the measured water quantity and agitated until a homogeneous solution is achieved.
Hand mixing is usually messy and unpleasant and can be time consuming. Additionally, it is subject to human error which can be fatal to chemical processes which require tight quality control such as photographic processing. In an economic sense, when an operator of a photographic processing machine is forced to stop printing photographs or X-rays because his chemical solution is depleted, the operation begins to lose money when the operator is forced to stop his work in order to replenish his processing chemicals by a hand mixing process.
Some prior art devices have attempted to automatically mix chemicals in order to solve some of the above mentioned problems. However, mixers of the prior art generally are manufactured only to use a given concentrate of dry or liquid concentrate chemical which usually involves the purchase of chemicals from the manufacturer of the mixing device. Additionally, many prior art units automatically add all the dry or liquid concentrate chemicals to be added at one time to a water solution thereby producing undesirable crystal precipitates which result from reactions occurring when the different chemicals hit the water solution simultaneously. Several units are extremely sophisticated and costly. Generally, devices of the prior art are not easily adaptable to individual needs and circumstances. If a chemical comes from a specific manufacturer requiring specific amounts of water to form a certain solution, the usual alternative is a hand mixing or like procedure.